jama jurabaev

Jama just started a Patreon page that includes a ton of Octane useage. His first offering is cinematic cityscapes, using Blender and Octane Standalone, but don't let that dissuade you because this training is top notch and the techniques will apply to any CG software. Check it out here: https://www.patreon.com/jama/overview (added 6/1/18)

Drew Nelson

An awesome talk recorded at the C4DSeattle meetup, from Drew Nelson who works at Amazon as a full-time motion designer. Packed with tons of Octane tips and tricks: https://www.youtube.com/watch?v=wsHO23Af3TE (added 5/23/18)

KITBASH 3D

Kitbash 3D not only makes amazing packs of cities with unique architectural styles, but they've started doing some awesome live streams, many of which include Octane use, from artists like Stuz0r, Mitch Myers, and myself! Check them out: https://www.youtube.com/channel/UCd3RJcJ0joXKuhUuAsUeTxA/videos (added 3/28/18)

This tutorial deserves special recognition, because it's the best breakdown I've seen on building your own PCs for GPU rendering, with Tom Glimps, Maxime Hacquard and Yvan Feusi: https://www.youtube.com/watch?v=XrOBvz454fU (added 6/4/18)

YVAN FEUSI

Also part of Motion Designers Community, but thought this would be worth a separate mention. Yvan is an amazing Octane artist, and he's created an in-depth tutorial on holograms in Octane. The shader tree gets pretty intense on this one! https://www.youtube.com/watch?v=H0avVhLJM3Q (added 1/23/18)

JOHANNES LINDQVIST

This guy is one of the best archviz artists I've ever seen. He has several tutorials on his YouTube page, and a ton on his Patreon page. Most of them are FStorm tutorials, but this renderer is extremely similar to Octane (it was made by a developer on Octane that quit to go and do his own thing). All 3DS Max as well, but if you want to do archviz work in C4D + Octane, this is where I'd start.

An awesome tut on creating a beautiful nature scene and using Mixamo data + XP to make autumn leaves gather and follow the character’s animation, then fly away into the wind: https://www.youtube.com/watch?v=H0SLVH28sWo (added 9/20/18)

Sketchy

AXIS FX

This guy has a mix of tutorials, some very cool like one on modeling a building face based off of an image, and then exporting as a height map to use as Octane displacement. Others are simpler tutorials, but could be helpful, but the one on SSS materials is nearly identical to David Brodeur's jelly tutorial, so that's pretty uncool. Still, included because this channel could be helpful to many: https://www.youtube.com/user/AxisDesignerGFX/videos (added 1/17/18)